Project Summary The goal of this Bioengineering Research Partnership application is pursue the next phase of development and application of Raman flow cytometry. In the initial project period, we designed and built the first Raman flow cytometers and demonstrated that they have the analysis speed and sensitivity for a wide range of applications. In the second project period, we will develop a Raman-enhanced flow cytometer with both Raman and fluorescence measurement capabilities, develop a new generation of uniform SERS nanotags, and use these in multiparameter analysis of cell signaling pathways. The result of this work will be a significant new tool for the highly multiparameter analysis of cell systems to help understand, diagnose, and prevent disease.